Crayfish, Crawdads, Yabbies, Ditch
FAQs on Crayfish Disease:
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Crawfish Pie, Let's Make a Crawfish Tank! By Gage
Harford, Invertebrates for Freshwater
Aquariums by Neale Monks,
Freshwater Shrimp, Crayfish,
Freshwater to Brackish
Freshwater Invertebrates/Use in
Aquariums, Freshwater Crustaceans for the Aquarium,
Fresh to Brackish
Crayfish translucent growths
I impulse bought a 3" Tangerine crayfish and now I'm scrambling to buy the
materials to cycle a 10g long tank but for now I'm keeping her in a small 2.5
gallon tub with a sponge filter until then. She recently molted (But lost some
limbs because she had horrible shell rot from the shop) and now its been 13 days
i have noticed growths from the stumps of her lost appendages!
<Indeed. These are likely 'benign' Protozoans, bacteria or fungi that grow
wherever there's plenty of dead organic material. They're benign in the sense
that they're not aggressive pathogens that will make your crayfish sick, but
they're still undesirable. An antibacterial and antifungal medication known to
be shrimp-safe (such as eSHa 2000) could be used here, alongside optimising
environmental conditions. To a great degree this sort of 'fluff' grows on
crayfish in tanks that have less than perfect cleanliness. The more gunk for
them to feed on, the more the Protozoans and fungus will spread onto your
i don't have a test kit yet so i cant tell the parameters but i do a lot of
partial water changes every other day and feed her veggies and sinking pellets.
She's acting so differently now and she's just scared of everything unlike
before (maybe its because she also lost her claws).. but i digress, the growths
look feathery and have spots in them, attached here is a photo i took of her in
an ice cream container while i was cleaning the sand in her tub (there was
rotting broccoli pieces hidden so it was stinking to high heaven)
<The photo isn't sharp enough to see exactly what the problem here, but for now,
I'd assume the benign fluff described above rather than an aggressive crayfish
parasite. Still, if you can get tack-sharp photos, sites like
PetShrimp.com have active forums with numerous experienced crustacean-keepers.>
Thank you for helping, I've added some antifungal meds (no copper) but i just
want to help her get better soon.
<Understood. Good luck, Neale.>
Re: Crayfish translucent growths
Thank you for the reply!!
Just adding again but here's another pic of Megatron i took the same day, is
this photo better?
<Not really. It's not so much the size of the photo as the fact the bit of
interest, the fluff around the legs, is basically a blurry mess with black
its got dark spots and it worries me to no end.
<They look like baby crayfish, what with the black spots and all! Cheers,
Crayfish; hlth., infectious; no pic
My name is luck
I would like know crayfish marron or Cherax Tenuimanus have Aphanomyces astaci
<Judging by? Looks, behavior? Have you read the wiki coverage:
Re: Health Concerns with Blue Crayfish 5/1/12
Hi again Bob,
Thanks for all your help in the past. Our blue Cray seems to be feeling
better now. Water levels have been stable for about three or so weeks now.
She's stopped laying on her side and looking miserable. We think she may
have just been in the process of laying her eggs when we saw her appearing
so uncomfortable. Her eggs are still black and she's retained all of them on
the underside of her tail. She's been eating every few days and is fairly
active. We're assuming that the eggs are unfertilized, but we'd read that if
they're unfertilized that crays will often drop them. She hasn't dropped any
yet and is very protective of them, so we're not sure what that means.
Recently we started noticing that some of the eggs were turning a pinkish
orange color and developing a fungus-looking cloud around them. She still
has black eggs that appear unaffected by this, but it definitely is
spreading, as now she has several large clumps of these orangish eggs coated
in a soft white fuzz. Are we correcting in assuming that her eggs have
If so, why hasn't she dropped her eggs by now, since they're likely
infertile and diseased?
<Sometimes they become so sticky, they stay in place>
I've been researching fungal infections and treatments for invertebrates
and some of them sound just plain scary! From what I've read Methylene Blue
seems really messy, dyes everything, and can mess with the balance of the
cycle - which is exactly what we don't want - and also seems to be best for
dips. We're not sure if that's the right solution for her.
<No treatment at all>
I've read that Malachite Green can be highly effective against fungus, but
dangerous and deadly to invertebrates. Is this true?
If so we certainly don't want to use it for our blue Cray, and that would
also nix out SeaChem Paraguard as it contains Malachite Green. Interpet
Anti-Fungus looked like it might be an option, but is hard to find in the USA
and we want to start her on treatments right away.
The options that look the most promising are Esha2000, Mardel Maroxy for
True Fungus (is there a difference between fungus and true fungus?),
<Yes; most of what people label "funguses" are actually bacteria... need
microscopic examination to tell>
Mardel Maracyn-Oxy (non-antibiotic), and Mardel Maracyn Powder or Tablets
(antibiotic). From what I've read they all appear to be non-toxic and safe
for invertebrates, and they all appear to treat fungus. Aside from that, I
have no idea what the difference is between all those Mardel products, I
don't know if we should be looking for an antibiotic or non-antibiotic
treatment, and I have no idea which ones would be best or recommended. Any
<Yes; to not treat period>
Also, now that the eggs have fungus, at what point will they fall off or
will she drop them or pick them off?
<Will be shed w/ the next moult>
Will the anti-fungal treatments help this problem, or should we do something
to scrape the eggs off of her? Is there a safe, non-traumatizing way to do
As always, thanks for your help!
P.S. I have also attached a few images of her with the fuzzy eggs.
Crawfish Question 1/14/10
I need your advice please. A week ago I purchased 6 regular crawfish
from a pet store. The store owner also talked me into buying two
additional ones what he called a "crimson" and a "Blue
Lobster". I ordered them the day before they were delivered to the
First what he called a crimson I found out after looking him up on the
net is a Procambarus clarkii. He is considerably larger then all the
<Oh! I did a "senior report" in Ecology on this species in
college! A substrate size preference study... P. clarkii has been
spread over a good deal of the U.S.... is quite common (though
invasive) in California where I live>
The "Blue Lobster" is very small in size and I really
couldn't find a species called "Blue Lobster". I have the
Blue guy in a separate tank.
<Mmm... please see here:
some species are predominantly blue, but can/do change with molts,
nutrition, water quality...>
Of the six regular crawfish I purchased two are "Reddish" in
color, Two are Brown with the fatter kind of claws and two are a very
light gray, almost white or see through.
I have the Clarkii and the other 6 in a 10 gallon tank with the 2
previous crawfish I had before them.
<Yikes! Are predaceous... will eat each other...>
After about three days home with them, I started to notice some
white-like- mold growing on the end of the Clarkii's tail. Soon
there after, I noticed that one of the Brown ones has some white bumps
on it, like tiny granules of salt sticking to the side of it's
head. Today I saw that one of the Reddish ones that has these salt like
things on top of his head and a Brown one has them growing down his
<Could be... Please read here:
Is this the WSSV I have been reading about?
<Mmm, White Spot Syndrome Virus... maybe>
I could not find a picture of what this looks like. I tired to take
pictures of mine, both in and out of the tank tonight but for some
reason my camera just will NOT take a clear picture of them, always
comes out blurry. Just the crawfish everything else in the background
is always in focus.
<Need either another camera or to see/check if this one has a
"close up" setting (look for a symbol that looks like a
Tonight one of the Reddish ones with these growths (a male) mated with
a brown one (female) that has no signs of this growth.
I bought these six originally to try and get them to have babies
because one of my original four had 12 this past November and they were
all eaten either by the other three of the feeder gold fish I keep in
the tank with them.
So now that you have the story what I would like your advice about
.Should I return just the infected crawfish to the store as I have a 14
day guarantee on them?
<I would return them all>
.Or do I return all of them?
.Should I keep them. Does this stuff just keep spreading and will it
hurt the feeder fish in the tank?
<The Procambarus will likely try to eat the goldfish...>
From what I read if this is WSSV there is no cure for it yet. By the
way the blue on is in a separate tank and shows no sign of this problem
Confused In Iowa
<Read a bit first... try sending along a good image or two; then
decide what you want to do. Bob Fenner>
Crayfish Plague -- 05/08/07 WetWeb Crew. John here.
<Hello John.> I need to know about the North American Crayfish
Plague. <Bad, bad voodoo. Pretty well wiped out the native crayfish
species here in the UK...> I'm thinking about buying the Red
Claw Crayfish, a native crayfish from Australia. The native crayfish we
have here in the eastern panhandle of West Virginia is the Orconectes
virilis, the Northern Crayfish. Would you guys know if my native crays
carry the Plague, or if the disease is in the waters here in West
Virginia. I need to know because i would like to use the water for my
Red Claws. <This is a difficult question to answer. You need to get
in contact with your local Fish & Wildlife agency. Assume any and
all crayfish can be carriers of the Plague, and keep native species
isolated from your exotic species accordingly.> Can this disease be
transmitted just by using the water, or does there have to be direct
contact with my native crays? The Northern Crayfish. <Virtually all
non-native crayfish are banned from trade in the UK in part because
they are taken by the government to be potential carriers of the
plague: http://www.defra.gov.uk/fish/freshwater/crayfish.htm#PET .
The Canadian fisheries web site remarks that a wide variety of
European, Australian, and North American crayfish can carry the plague
and/or suffer from it: http://www.pac.dfo-mpo.gc.ca/sci/shelldis/pages/cpfdcy_e.htm
. So, in short, unless you can obtain categorical, scientific proof to
the contrary, assume the plague can hop from native to exotic species
easily. Since the plague is a fungal infection, it will be transmitted
by sharing water, nets, and aquarium equipment, so you *will* need to
maintain proper isolation between native crayfish and exotics.> It
is very important that i have this information. Can you PLEASE HELP?
<Hope this helps.> Thanks for your time. Regards John <Cheers,
Crayfish With Worms? Parasite, or Symbiont? - 12/06/2005 Hi,
<Hello.> I am a Veterinarian with very limited, if any,
experience with marine animals. <Good thing crays are freshwater,
then! <grin> > << <giggle> >> My
son's 7th grade class has an aquarium with crayfish and he tells me
that they have white worms on them, about 1/2" long. My question
is, if he acquires a worm for me and I can determine whether it is a
worm or a fluke, what would be the meds that I could use? Please
include dosages and exactly how to administer the meds. I do have
liquid Fenbendazole but it is thick and white, is this OK to use in
water? Please help, if possible. <The real question here is whether
these worms are actually a problem.... or whether they may be a
*benefit* to the class Cray. It sounds like these are Branchiobdellids,
which are often found on crayfish, and pose no threat to the animals.
Though perhaps a little unsightly, these guys do seem to offer some
benefit to the Cray, and apparently even consume damaged eggs of
carrying females while not harming healthy eggs. Were it me/my class,
I'd probably leave the worms be, and maybe make a sort of a project
out of it to count the crayfish's "helpers" every now and
then, and have a chance to learn about symbiosis. Here is a link with a
bit of information:
Worms & Crayfish .... Also, I recommend doing a Google search
on "Branchiobdellid annelids"; using this term in Google
Scholar might be a good idea, too. http://scholar.google.com/ . And....
to offer just a little extra (less satisfying) information....
There's just not a whole lot known or done regarding invertebrate
pathology in pet inverts. The only real information in this area is in
relation to the food industry, and culturing shrimp for food. The
solution to pathogenic problems in the food shrimp industry is to
destroy the affected stock, sterilize the affected system, and start
from scratch. Of course, that won't help hobbyists, or hobbyist
shrimp , and it certainly won't help a classful of 7 year olds with
a beloved pet crawdaddie. This is a pet peeve of mine, and something
that I hope will be remedied in the future.... One of my dreams is to
go back to school for fish pathology, and try to forge a bit of a path
for myself in invertebrate pathology.... but I have a hundred other
dreams I desperately wish to pursue, so we'll see what happens.>
Thanks, -Robin Rosen-Sharp DVM <All the best to you, your son, his
class, and their Cray, -Sabrina>